DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0043] With reference to the accompanying drawings, description will be given of a preferred embodiment of a print system according to the present invention.

[0044] FIG. 1 is a front sectional view of an over-the-counter digital photo print system to which the print system according to the present invention has been applied. This over-the-counter digital photo print system is a print machine with TA printers that employ a TA method. With the TA method, a user inserts a recording medium such as Smart Media into a media insertion slot 89 and then loads money into the system to print digital images stored in the recording medium, on TA paper.

[0045] This print machine 70 has a touch panel 98 disposed on its front surface and a liquid crystal display 80 disposed at the top of the front surface. While viewing the display 80, the user operates the touch panel 98 to input required information such as a print size or the number of prints. Printers 90, 92, 94, and 96 are installed inside the print machine 70 in its middle and lower areas. Each of the printers 90 to 96 can print digital images. Accordingly, with the print machine 70 according to the present embodiment, the four printers can print images. An output port 150 is formed at the bottom of the outside front surface so that printed TA paper of a size specified by the used can be discharged through the output port 150. A coin machine (shown at 88 in FIG. 2) is mounted in this area.

[0046] FIG. 2 is a block diagram showing the configuration of hardware in the print machine 70.

[0047] The user inserts a recording medium into the media insertion port 89 (FIG. 1). A hard disk controller 74 operates control software recorded in a hard disk (not shown). Image data is recorded in the recording medium after being compressed into a predetermined format. A CPU 72 instructs a media reader controller 82 to read the image data to acquire required image data from the recording media. The CPU 72 then expands the image data to restore it to the original. The CPU 72 further subjects the data to a required image process to store the processed data in a RAM 76.

[0048] Through the touch panel 98, the user inputs the required information such as the print size or the number of prints. The inputted information is displayed on the display 80 and transmitted to a serial controller 86. The display 80 is operated by a display controller 78. The coin machine 88 checks whether the user has loaded the amount of money displayed on the display, on the basis of the information inputted through the touch panel 98. If the required amount of money has been loaded, the image data stored in the RAM 76 is transmitted to the printers 90, 92, 94, and 96 via a SCSI controller 84 as a print job. These processes are controlled by the CPU 27.

[0049] The printers 90 to 96 employs a print method called the “TA method”. This method uses TA paper which develops a color when heated and which fixes the color when irradiated with light of a predetermined wavelength. Description will be given of arrangements and operations relating to a print process executed by each printer using the TA method. FIG. 3 is a block diagram showing the arrangements relating to the print process executed by each printer using the TA method.

[0050] As shown in FIG. 3, a system controller 10 is a processing section that integrally controls the whole system. The system controller 10 is connected to the SCSI controller 84 in the print machine 70. The system controller 10 receives jobs from the SCSI controller 84. The system controller 10 is adapted to deliver image data to each control block and give the control block various instructions on the execution of printing and the like. The CPU 72 gives the system controller 10 instructions on various processes on the basis of the touch panel 98, operated by the user. Operation programs for the system controller 10 are recorded in an EEPROM 18.

[0051] A job delivered by the SCSI controller 84 is stored in a memory 22 via the system controller 10 and a memory controller 20. Specifically, the memory controller 20 is a processing section that controls data writes to and reads from the memory 22. The memory controller 20 operates to store image data such as print images in the memory 22, the print images being received from the SCSI controller 84 and system controller 10. In accordance with an instruction from the system controller 10, the image data such as print images stored in the memory 22 is outputted to a print controller 28. The memory 22 stores the ID number of a unique SCSI of the printer. That is, each of the printers 90, 92, 94, and 96 stores the ID number of the SCSI unique to the printer.

[0052] The print controller 28, a head driving circuit 30, a paper carriage control section 32, and a fixation control section 34, all of which are shown in FIG. 3, are control blocks used to execute printing. These control blocks synchronously perform various control operations in accordance with an instruction on the execution of printing which instruction is given by the system controller 10.

[0053] Then, description will be given of TA paper used in this printer. As shown in FIG. 4, TA paper 50 is formed of three layers sequentially stacked on a surface of a support 52, the three layers including a cyan (C) color developing layer 54, a magenta (M) color developing layer 56, and a yellow (Y) color developing layer 58. When the C color developing layer 54, the M color developing layer 56, and the Y color developing layer 58 are subjected to corresponding quantities of heat, a C, M, and Y colors of densities (gradation) corresponding to the quantities of heat are developed. Furthermore, when the color developing layers other than the C color developing layer 54, i.e. the M color developing layer 56 and the Y color developing layer 58 are irradiated with light of corresponding wavelengths (about 365 nm for the M color developing layer 56 and about 425 nm for the M color developing layer 58), the developed colors are fixed.

[0054] Upon receiving an instruction on the execution of printing from the system controller 10, the print controller 28 acquires image data on the print image stored in the memory 22 by the memory controller 20. On the basis of the image data on the print image, the print controller 28 then sets gradations (print gradation values) for the C, M, and Y colors in each pixel of the print image within the range of, for example, an 8-bit resolution (0 to 255). The print controller 28 then outputs data on the print gradation values for the C, M, and Y colors in each pixel of the print image to the head driving circuit 30 synchronously with the traveling of TA paper line by line in a direction (main scanning direction) perpendicular to the traveling direction (sub-scanning direction).

[0055] At this time, a CPU 152 calculates data required to generate a mark dot with an optimum gradation value in an area of the TA paper specified in connection with the storage of the ID number of the SCSI unique to the printer in the memory 22, the mark dot being generated from image data present around the specified area. The system controller 10 then outputs the data to the control blocks via the memory controller 20, the control blocks including the print controller 28, the head driving circuit 30, the paper carriage control section 32, and the fixation control section 34.

[0056] Upon receiving the data on the print gradation values for the C, M, and Y colors from the print controller 28 as described above, the head driving circuit 30 controls voltages applied to dot-by-dot heating elements in a thermal head 38 arranged in the main scanning direction as well as the time (pulse width) required to energize the heating elements; this control is carried out synchronously with the traveling of the TA paper, on the basis of the print gradation values. This allows the quantity of heat provided to each point of the TA paper by the corresponding dot-by-dot heating element in the thermal head 36 to be controlled in accordance with the print gradation values for the C, M, and Y colors. Thus, in the color developing layers of the TA paper, the respective colors are developed which have densities corresponding to the print gradation values specified by the print controller 28.

[0057] Upon receiving an instruction on the execution of printing from the system controller 10, the paper carriage control section 32 feeds TA paper from a TA paper housing section to a TA paper print processing section. The TA paper housing section has a roll of TA paper 50 loaded in it. Furthermore, after feeding the TA paper to the print processing section, the paper carriage control section 32 uses a motor to drive a capstan roller 38 to drive the TA paper synchronously with print processes including color development and fixation. At this time, the system controller 10 uses a home position (HP) sensor 40 to detect that the TA paper is located at its home position. The system controller 10 then causes the paper carriage control section 32 to reciprocate the TA paper using the home position as a reference.

[0058] The fixation control section 34 controls the lighting and extinction of a Y fixing fluorescent lamp 42 and an M fixing fluorescent lamp 44 synchronously with the process executed by the thermal head 36 to develop the colors of the Y and M light developing layers in the TA paper. The Y fixing fluorescent lamp 42 has a light emission characteristic indicated by a peak wavelength of at least 425 nm. When the Y fixing fluorescent lamp 42 is lighted to irradiate the TA paper with light with the above wavelength, the Y color developing layer in the TA paper is fixed. On the other hand, the M fixing fluorescent lamp 44 has a light emission characteristic indicated by a peak wavelength of at least 365 nm. When the M fixing fluorescent lamp 44 is lighted to irradiate the TA paper with light with the above wavelength, the M color developing layer in the TA paper is fixed.

[0059] FIG. 5 is a layout drawing showing an embodiment of the arrangement of the members of the print processing section of each of the printers 90 to 96, which section executes print processes including the development and fixation of the colors on the TA paper.

[0060] As shown in FIG. 5, the print processing section has the following components sequentially arranged on a carriage path along which the TA paper 50 is fed: the capstan roller 38, a nip roller 39, the thermal head 36, a platen roller 62, a cutter 63, a light emitting LED 40A and a light receiving sensor 40B constituting an HP sensor 40, a Y fixing fluorescent lamp 42, and an M fixing fluorescent lamp 44.

[0061] The TA paper 50 fed from the upstream side of the carriage path is sandwiched between the capstan roller 38 and the nip roller 39 and also between the thermal head 36 and the platen roller 62. During a print process, the capstan roller 38 is rotatively moved by the motor to reciprocate the TA paper 50 in the sub-scanning direction, shown by arrows A and A′.

[0062] The thermal head 36 has a plurality of heating elements arranged in a line in the main scanning direction, which is perpendicular to the sub-scanning direction, in which the TA paper 50 is carried. The heating elements provide heat to the TA paper 50 line by line in the main scanning direction synchronously with the carriage of the TA paper 50 in the printing direction shown by the arrow A in the figure. This causes the color developing layers to develop the respective colors.

[0063] The LED 40A of the HP sensor 40 floodlights the light receiving sensor 40B across the carriage path for the TA paper 50. The HP sensor 40 can detect the presence of the TA paper 50 on the basis of a detection signal from the light receiving sensor 40B. A detection signal outputted by the light receiving sensor 40B is inputted via an A/D converter (not shown) to the system controller 10, shown in FIG. 3.

[0064] The system controller 10 carries out detection as to whether or not light provided by the LED 40A is received by the light receiving sensor 40B, to determine whether or not the TA paper 50 is located at the position of the HP sensor 40. Then, the system controller 10 detects the switching between the period when the leading end of the TA paper is located at the position of the HP sensor 40 and the period when the leading end of the TA paper is not located at the position of the HP sensor 40, to carry out detection as to whether or not the leading end of the TA paper 50 has been carried to the position of the HP sensor 40. Thus, the TA paper is aligned using, as the home position of the TA paper 50, the point in time when the leading end of the TA paper 50 reaches the position of the HP sensor 40. This position is used as a reference to synchronize the carriage of the TA paper 50 with the print processes including the development and fixation of the colors.

[0065] Description will be given of a mechanism that generates mark dots in a predetermined area in the TA paper 50, in the printers 90 to 96, configured as described above.

[0066] Since the memory 22 stores the ID number of the SCSI unique to the printer, mark dots are provided in a specified area corresponding to the ID number. The mark dots are provided in one area on the left side of a print 51 (having a size specified by the user and into which the TA paper is cut), specifically in the center of one of the eight pieces into which the size of the left side of the print is divided in the printing direction. In the present embodiment, since the four printers are provided, the mark dots are provided in the lower four divisions on the left side as shown in FIG. 6. The printer is determined depending on which division contains the mark dots.

[0067] FIG. 7 is an enlarged diagram of a part B in FIG. 6, showing mark dots and dots for mark gradation values. That is, this figure is an enlarged view of the above described area containing the mark dots. Two dots are provided in the printing direction, while three dots are provided in the direction orthogonal to the printing direction. Thus, in total, six dots are provided. The dots present around the mark dots are reference dots used to determine a gradation value for the mark dots.

[0068] The gradation value for the mark dots deviates from an average value for the mark dot gradation value reference dots by 128 gradations. Then, the relationship between the gradation value for the mark dots and the average value for the surrounding mark gradation value reference dots is as shown in FIG. 8. For example, if the surrounding mark gradation value reference dots have an average value of 255, the mark dots have a gradation value of 128. With the printing method using the above described TA printers, to allow a dot to have the above gradation value, a dot is first generated for each of the three colors, Y, M, and C. Then, the three colors are superimposed on one another to create a dot of the desired color.

[0069] The deviation by 128 gradations causes the mark dots to have an unnoticeable color but can still be distinguished from the surrounding colors to allow the user to discover them easily when examining the print consciously.

[0070] The use of the above mark dots enables the user to discover the mark that is unnoticeable on the print when examining the print consciously.

[0071] According to the present embodiment, the mark dots are provided on a print. Thus, if any of the prints discharged to the output port 150 is defective (for example, it has excessively dark or light colors or is striped), the printer having produced this print can be determined from the position of the mark dots provided on the print. Accordingly, the cause of the defect can be determined promptly and accurately.

[0072] Furthermore, the user cannot find the mark dots without examining the print consciously. This prevents the quality of prints themselves from being degraded.

[0073] In the present embodiment, the mark dots are displayed on prints to identify the printers having produced these prints. However, the present invention is not limited to this aspect. Unnoticeable characters or patterns may be used with the analysis of the surrounding gradation values.

[0074] Moreover, in the present embodiment, the mark dots are provided on the same surface as that on which images are printed. This enables the application of a typical printing structure, thus eliminating the need for complicated facilities. Therefore, an inexpensive print system can be provided.

[0075] The printers in the print machine may be sublimation type thermal transfer printers or ink jet type printers.

[0076] It should be understood, however, that there is no intention to limit the invention to the specific forms disclosed, but on the contrary, the invention is to cover all modifications, alternate constructions and equivalents falling within the spirit and scope of the invention as expressed in the appended claims.